feat(cargo-build): Add ability to compile specified binaries.

risc0/build/src/docker.rs

@@ -35,7 +35,12 @@ const DOCKER_IGNORE: &str = r#"
 const TARGET_DIR: &str = "target/riscv-guest/riscv32im-risc0-zkvm-elf/docker";
 
 /// Build the package in the manifest path using a docker environment.
-pub fn docker_build(manifest_path: &Path, src_dir: &Path, features: &[String]) -> Result<()> {
+pub fn docker_build(
+    manifest_path: &Path,
+    src_dir: &Path,
+    binaries: &[String],
+    features: &[String],
+) -> Result<()> {
     let manifest_path = manifest_path
         .canonicalize()
         .context(format!("manifest_path: {manifest_path:?}"))?;
@@ -69,14 +74,24 @@ pub fn docker_build(manifest_path: &Path, src_dir: &Path, features: &[String]) -
         let temp_dir = tempdir()?;
         let temp_path = temp_dir.path();
         let rel_manifest_path = manifest_path.strip_prefix(&src_dir)?;
-        create_dockerfile(&rel_manifest_path, temp_path, pkg_name.as_str(), features)?;
+        create_dockerfile(
+            &rel_manifest_path,
+            temp_path,
+            pkg_name.as_str(),
+            binaries,
+            features,
+        )?;
         build(&src_dir, temp_path)?;
     }
     println!("ELFs ready at:");
 
     let target_dir = src_dir.join(TARGET_DIR);
     for target in root_pkg.targets.iter() {
         if target.is_bin() {
+            if !binaries.is_empty() && !binaries.contains(&target.name) {
+                println!("Skipping target: {}", target.name);
+                continue;
+            }
             let elf_path = target_dir.join(&pkg_name).join(&target.name);
             let image_id = compute_image_id(&elf_path)?;
             let rel_elf_path = Path::new(TARGET_DIR).join(&pkg_name).join(&target.name);
@@ -94,6 +109,7 @@ fn create_dockerfile(
     manifest_path: &Path,
     temp_dir: &Path,
     pkg_name: &str,
+    binaries: &[String],
     features: &[String],
 ) -> Result<()> {
     let manifest_env = &[("CARGO_MANIFEST_PATH", manifest_path.to_str().unwrap())];
@@ -111,6 +127,11 @@ fn create_dockerfile(
     ];
 
     let mut build_args = common_args.clone();
+    let binaries_str = binaries.join(",");
+    if !binaries.is_empty() {
+        build_args.push("--bin");
+        build_args.push(&binaries_str);
+    }
     let features_str = features.join(",");
     if !features.is_empty() {
         build_args.push("--features");

risc0/build/src/lib.rs

@@ -401,6 +401,11 @@ fn build_guest_package<P>(
         cargo_command("build", &[])
     };
 
+    let binaries_str = guest_opts.bin.join(",");
+    if !guest_opts.bin.is_empty() {
+        cmd.args(&["--bin", &binaries_str]);
+    }
+
     let features_str = guest_opts.features.join(",");
     if !features_str.is_empty() {
         cmd.args(&["--features", &features_str]);
@@ -500,6 +505,9 @@ pub struct GuestOptions {
     /// Features for cargo to build the guest with.
     pub features: Vec<String>,
 
+    /// Binary names to build.
+    pub bin: Vec<String>,
+
     /// Use a docker environment for building.
     pub use_docker: Option<DockerOptions>,
 }
@@ -557,6 +565,7 @@ pub fn embed_methods_with_options(mut guest_pkg_to_options: HashMap<&str, GuestO
             docker_build(
                 guest_pkg.manifest_path.as_std_path(),
                 &src_dir,
+                &guest_opts.bin,
                 &guest_opts.features,
             )
             .unwrap();

risc0/cargo-risczero/src/commands/build_guest.rs

@@ -26,6 +26,10 @@ pub struct BuildGuest {
     #[arg(long)]
     pub manifest_path: PathBuf,
 
+    /// Specify binaries to build.
+    #[clap(long, value_delimiter = ',')]
+    pub bin: Vec<String>,
+
     /// Feature flags passed to cargo.
     #[arg(long, value_delimiter = ',')]
     pub features: Vec<String>,
@@ -34,6 +38,6 @@ pub struct BuildGuest {
 impl BuildGuest {
     pub fn run(&self) -> Result<()> {
         let src_dir = std::env::current_dir().unwrap();
-        risc0_build::docker_build(&self.manifest_path, &src_dir, &self.features)
+        risc0_build::docker_build(&self.manifest_path, &src_dir, &self.bin, &self.features)
     }
 }

risc0/zkvm/methods/build.rs

@@ -41,13 +41,15 @@ fn main() {
         (
             "risc0-zkvm-methods-guest",
             GuestOptions {
+                bin: vec![],
                 features: vec![],
                 use_docker,
             },
         ),
         (
             "risc0-zkvm-methods-std",
             GuestOptions {
+                bin: vec![],
                 features: vec!["test_feature1".to_string(), "test_feature2".to_string()],
                 use_docker: None,
             },